Human Spire Interacts with the Barbed End of the Actin Filament
Human Spire Interacts with the Barbed End of the Actin Filament
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DOI：
10.1016/j.jmb.2010.12.045
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发表时间：
2011-04-22
影响因子：
5.6
通讯作者：
Oda, Toshiro
中科院分区：
文献类型：
--
作者：
Ito, Takuto;Narita, Akihiro;Oda, Toshiro
SPIRE是一种肌动蛋白核因子，在细胞中的特定位置启动肌动蛋白聚合。与Arp2/3复合体类似，SPIRE最初被认为在产生新的肌动蛋白细丝时与肌动蛋白细丝的尖端结合。随后，据报道，SPIRE与带刺的末端(B端)有关；因此，关于SPIRE与之相互作用的末端，仍未达成共识。在这里，我们报告了直接证据，在SPIRE加速肌动蛋白聚合的条件下，SPIRE结合到肌动蛋白细丝的B端。在电子显微镜下，我们通过金纳米颗粒标记组氨酸标记的尖端，可视化了结合在细丝上的尖端的位置，并通过图像分析确定了肌动蛋白细丝的极性。此外，我们的结果表明，通过一个金纳米颗粒连接的多个螺旋提高了肌动蛋白聚合的速度。SPIRE的B-端结合为了解其在细胞内的作用机制提供了基础。(C)2011爱思唯尔有限公司。保留所有权利。
Spire is an actin nucleator that initiates actin polymerization at a specific place in the cell. Similar to the Arp2/3 complex, spire was initially considered to bind to the pointed end of the actin filament when it generates a new actin filament. Subsequently, spire was reported to be associated with the barbed end (B-end); thus, there is still no consensus regarding the end with which spire interacts. Here, we report direct evidence that spire binds to the B-end of the actin filament, under conditions where spire accelerates actin polymerization. Using electron microscopy, we visualized the location of spire bound to the filament by gold nanoparticle labeling of the histidine-tagged spire, and the polarity of the actin filament was determined by image analysis. In addition, our results suggest that multiple spires, linked through one gold nanoparticle, enhance the acceleration of actin polymerization. The B-end binding of spire provides the basis for understanding its functional mechanism in the cell. (C) 2011 Elsevier Ltd. All rights reserved.